ftk学习记（list篇）

    在开始今天的list主题之前，先看一下icon的运行效果。

    今天说的list其实和这个icon差不多。大家只需要把这些icon想像成一条一条的item就可以了。同样，list的demo代码中也会有一个more的button，每次单击一下，就会增加几个item。闲话不多说，先看一下demo代码是怎么样的。

#include "ftk.h"

#include "ftk_list_view.h"
#include "ftk_list_render_default.h"
#include "ftk_list_model_default.h"

#define IDC_TEST_BUTTON 1000
int g_index = 0;
FtkBitmap*  left_icon = NULL;
FtkBitmap* right_icon = NULL;

static Ret button_quit_clicked(void* ctx, void* obj)
{
  ftk_quit();

  return RET_OK;
}

static Ret button_more_clicked(void* ctx, void* obj)
{
  int i = 0;
  char text[32] = {0};
  FtkListItemInfo info = {0};
  FtkListModel* model = ctx;

  for(i = 0; i < 4; i++)
  {
    g_index++;
    ftk_snprintf(text, sizeof(text), "item%04d", g_index);
    info.text = (text);
    info.left_icon = left_icon;
    info.right_icon = right_icon;
    info.type = g_index%4;
    ftk_list_model_add(model, &info);
  }

  return RET_OK;
}

Ret on_item_clicked(void* ctx, void* list)
{
  FtkListItemInfo* info = NULL;
  FtkListModel* model = ftk_list_view_get_model(list);
  int i = ftk_list_view_get_selected(list);

  ftk_list_model_get_data(model, i, (void**)&info);
  if(info != NULL)
  {
    info->state = !info->state;
  }
  ftk_logd("%s: %d/%d\n", __func__, 
    ftk_list_view_get_selected(list),
    ftk_list_model_get_total(model));

  return RET_OK;
}

int FTK_MAIN(int argc, char* argv[])
{
  int width = 0;
  int height = 0;
  char text[32] = {0};
  FtkWidget* win = NULL;
  FtkWidget* button = NULL;
  FtkWidget* list = NULL;
  FtkListModel* model = NULL;
  FtkListRender* render = NULL;
  FtkListItemInfo info = {0};
  char filename[FTK_MAX_PATH+1] = {0};
  ftk_init(argc, argv);
  
  win = ftk_app_window_create();
  width = ftk_widget_width(win);
  height = ftk_widget_height(win);
  
  list = ftk_list_view_create(win, 10, 5, width - 20, 3 * height/4-5);
  ftk_list_view_set_clicked_listener(list, on_item_clicked, NULL);

  model = ftk_list_model_default_create(10);
  render = ftk_list_render_default_create();
  ftk_snprintf(filename, FTK_MAX_PATH, "%s/alarm/%s",TESTDATA_DIR, FTK_STOCK_IMG_SUFFIX);
  left_icon = ftk_bitmap_factory_load(ftk_default_bitmap_factory(), filename);
  ftk_snprintf(filename, FTK_MAX_PATH, "%s/search/%s",  TESTDATA_DIR, FTK_STOCK_IMG_SUFFIX);
  right_icon = ftk_bitmap_factory_load(ftk_default_bitmap_factory(), filename);

  g_index = 0;
  for(g_index = 0; g_index < 4; g_index++)
  {
    ftk_snprintf(text, sizeof(text), "item%04d", g_index);
    info.text = (text);
    info.left_icon = left_icon;
    info.right_icon = right_icon;
    info.type = g_index%4;
    ftk_list_model_add(model, &info);
  }

  ftk_list_view_init(list, model, render, 40);
  ftk_list_model_unref(model);

  button = ftk_button_create(win, width/4, 3 * height/4 + 5, width/4, 60);
  ftk_widget_set_text(button, "more");
  ftk_button_set_clicked_listener(button, button_more_clicked, model);

  button = ftk_button_create(win, width/2, 3 * height/4 + 5, width/4, 60);
  ftk_widget_set_text(button, "quit");
  ftk_button_set_clicked_listener(button, button_quit_clicked, win);
  ftk_window_set_focus(win, button);

  ftk_widget_set_text(win, "list view demo");
  ftk_widget_show_all(win, 1);
  ftk_widget_set_attr(win, FTK_ATTR_QUIT_WHEN_CLOSE);

  ftk_run();

  return 0;
}

    细细看来，代码的流程非常眼熟。大家可以把注意力集中到list、model、render和info这几个变量上。其中，尤其需要注意的是list和info。list提供了一个显示空间，而info则用来表示每一个list的item。当然，每一个list item被选中的时候，on_item_clicked函数都会被调用。当然，除此之外系统也创建了两个button，两个callback函数分别是button_quit_clicked和button_more_clicked。具体的细节分析一下代码即可。

    好了，说了这么多，还是等着看下次的运行效果吧。